Branch circuit or Feeder

[Steelhead]

In determining if a circuit will be a feeder or a branch circuit, would you consider a circuit breaker that is an integral part of a piece of equipment, the final overcurrent device? Or would you consider the fused disconnect supplying that piece of equipment the final overcurrent device?

Thanks.

 

[GoldDigger]

Unless the device is a panel, integral OCPD should not matter.
And supplemental OCPD such as a fused disconnect on a CB protected branch should not count either.

Tapatalk!

 

[Steelhead]

Unless the device is a panel, integral OCPD should not matter.
And supplemental OCPD such as a fused disconnect on a CB protected branch should not count either.

Tapatalk!

Please forgive me, but could you rephrase your answer? I'm not sure what you mean.

 

[Smart $]

OCP that is part of utilization equipment is considered supplementary OCP and does not qualify as the required branch circuit OCP [240.10].

 

[Steelhead]

OCP that is part of utilization equipment is considered supplementary OCP and does not qualify as the required branch circuit OCP [240.10].

That clears it up, thanks!

 

[petersonra]

OCP that is part of utilization equipment is considered supplementary OCP and does not qualify as the required branch circuit OCP [240.10].

I am not sure I see that in 240.10.

240.10 Supplementary Overcurrent Protection. Where
supplementary overcurrent protection is used for luminaires,
appliances, and other equipment or for internal circuits and
components of equipment, it shall not be used as a substitute
for required branch-circuit overcurrent devices or in place of
the required branch-circuit protection. Supplementary overcurrent
devices shall not be required to be readily accessible.

IMO, supplementary OCPD devices are specific types of fuses or CBs, and not defined by where they are in a circuit.

 

[Smart $]

I am not sure I see that in 240.10.



IMO, supplementary OCPD devices are specific types of fuses or CBs, and not defined by where they are in a circuit.

The NEC does not define or elaborate...

 

[Dennis Alwon]

I am not sure I see that in 240.10.



IMO, supplementary OCPD devices are specific types of fuses or CBs, and not defined by where they are in a circuit.

I have to agree with Smart-- the supplementary overcurrent protective device is generally part of the equipment. In lighting it may be an inline fuse but with a/c units where the breaker is part of the equipment then that is considered supplementary.

 

[petersonra]

I have to agree with Smart-- the supplementary overcurrent protective device is generally part of the equipment. In lighting it may be an inline fuse but with a/c units where the breaker is part of the equipment then that is considered supplementary.

I do not disagree that supplementary protection is generally part of the equipment. What I disagree with is that an OCPD that is part of a piece of equipment is always supplementary.

 

[Smart $]

I do not disagree that supplementary protection is generally part of the equipment. What I disagree with is that an OCPD that is part of a piece of equipment is always supplementary.

I don't believe anyone is suggesting anything to the contrary. The NEC doesn't draw a fine line of distinction. For example, say you supply an electrical cabinet of a machine which has a main breaker and then distributes power to several component loads external to the cabinet through additional OCP and controlling means. Most would call the supply circuit a feeder, even though the machine's OCP is outside the purview of the NEC. However, I think we can agree if the equipment is in itself self-contained utilization equipment, integral OCP would be supplementary.

 

[petersonra]

However, I think we can agree if the equipment is in itself self-contained utilization equipment, integral OCP would be supplementary.

I don't agree.

i don't see how you get past the basic definition of supplementary OCPD which comes from how it is listed.

Are we going to claim that a UL489 CB can't provide branch circuit protection because someone put it in a box with some other equipment?

Overcurrent Protective Device, Branch-Circuit. A device
capable of providing protection for service, feeder, and
branch circuits and equipment over the full range of overcurrents
between its rated current and its interrupting rating.
Branch-circuit overcurrent protective devices are provided
with interrupting ratings appropriate for the intended
use but no less than 5000 amperes.

Overcurrent Protective Device, Supplementary. A device
intended to provide limited overcurrent protection for
specific applications and utilization equipment such as luminaires
and appliances. This limited protection is in addition
to the protection provided in the required branch circuit
by the branch-circuit overcurrent protective device.

The definitions are not as much help as we might want, but it would appear it can't be both simultaneously, so if it meets the definition of a branch circuit OCPD it can't be a supplementary OCPD.

JMO.

 

[kwired]

I don't believe anyone is suggesting anything to the contrary. The NEC doesn't draw a fine line of distinction. For example, say you supply an electrical cabinet of a machine which has a main breaker and then distributes power to several component loads external to the cabinet through additional OCP and controlling means. Most would call the supply circuit a feeder, even though the machine's OCP is outside the purview of the NEC. However, I think we can agree if the equipment is in itself self-contained utilization equipment, integral OCP would be supplementary.

If said machine is supplied by a feeder tap is where the distinction gets blurred, as that overcurrent device is more of a necessity then an option in that instance.

 

[Smart $]

I don't agree.

i don't see how you get past the basic definition of supplementary OCPD which comes from how it is listed.

Are we going to claim that a UL489 CB can't provide branch circuit protection because someone put it in a box with some other equipment?





The definitions are not as much help as we might want, but it would appear it can't be both simultaneously, so if it meets the definition of a branch circuit OCPD it can't be a supplementary OCPD.

JMO.

Please name or describe a piece of self-contained utilization equipment which has integral ocpd and an NEC branch circuit after that ocpd.

 

[GoldDigger]

Please name or describe a piece of self-contained utilization equipment which has integral ocpd and an NEC branch circuit after that ocpd.

Are you saying that if there is no NEC branch circuit after the OCPD, the NEC circuit before the OCPD cannot be a feeder?
Makes sense to me.


Tapatalk!

 

[Smart $]

Are you saying that if there is no NEC branch circuit after the OCPD, the NEC circuit before the OCPD cannot be a feeder?
Makes sense to me.

No, that's not what I'm saying...



But it is a logical deduction from and the intent of what I'm saying.

 

[mwm1752]

Lets say you have a 20a circuit for elevator car lights -- the OCPD is located outside the elevator room -- once inside the room a single disconnect 15A breaker is fed thru to the car light circuit -- Where is the branch/feeder circuit conductor protection located? Is here supplementary OCP?
Now the elevator room has a control box in which the same 20A circuit is fed into -- this time the feed thru breaker is 20A --
Where is the branch/feeder circuit conductor protection located? Is here supplementary OCP?

 

[jim dungar]

Please name or describe a piece of self-contained utilization equipment which has integral ocpd and an NEC branch circuit after that ocpd.

Say you have a CNC machine with an integral 'main' OCPD fed by 208Y/120V. Inside of the CNC cabinet there are three circuit breakers, among other circuits. CB1 (5A) feeds a cord connected oil sump pump located below the machine on a pull out tank, CB2 (7A) feeds a cord connected removable chip conveyor, and CB3 (2A) which feeds a convenience receptacle mounted on the front exterior of machine.

Which circuit breakers need to be branch circuit rated (e.g. UL489) and which can be supplemental (e.g. UL1077)?

 

[Smart $]

Say you have a CNC machine with an integral 'main' OCPD fed by 208Y/120V. Inside of the CNC cabinet there are three circuit breakers, among other circuits. CB1 (5A) feeds a cord connected oil sump pump located below the machine on a pull out tank, CB2 (7A) feeds a cord connected removable chip conveyor, and CB3 (2A) which feeds a convenience receptacle mounted on the front exterior of machine.

Which circuit breakers need to be branch circuit rated (e.g. UL489) and which can be supplemental (e.g. UL1077)?

Isn't there only one piece to a piece of self-contained utilization equipment???

 

[Smart $]

Lets say you have a 20a circuit for elevator car lights -- the OCPD is located outside the elevator room -- once inside the room a single disconnect 15A breaker is fed thru to the car light circuit -- Where is the branch/feeder circuit conductor protection located? Is here supplementary OCP?
Now the elevator room has a control box in which the same 20A circuit is fed into -- this time the feed thru breaker is 20A --
Where is the branch/feeder circuit conductor protection located? Is here supplementary OCP?

I'm not familiar with elevator design, but my guess from your description is the OCPD outside the elevator room is a feeder OCPD, the other two are branch OCPD.

 

[mwm1752]

I'm not familiar with elevator design, but my guess from your description is the OCPD outside the elevator room is a feeder OCPD, the other two are branch OCPD.

The first circumstance describes two branch/feeder circuits
IMO the second circumstance has only one OCPD for the branch/feeder circuit & the secondary protection is in the control box.